Apparatus for carrying out a diffusion transfer process



H. KLEINSTRA Aug. 8, 1967 APPARATUS FOR CARRYING OUT A DIFFUSIONTRANSFE-R PROCESS 5 Sheets-Sheet. 1

Filed Nov. 12, 1963 FIG. 2

INVENTOR. HA Aw Mam/arm Omw, WCOM M 4 57 Aug. 8, 1967 H. KLEINSTRA 3,334,564

APPARATUS FOR CARRYING OUT A DIFFUSION TRANSFER PROCESS I Filed NOV. 12. 1963 5 Sheets-Sheet INVENTOR.

HA PM KL E/A/J TAM H. KLEINSTRA Aug. 8, 1967 APPARATUS FOR CARRYING QUT A DIFFUSION TRANSFER PROCESS 5 Sheets-Sheet Filed Nov. 12, 1963 United States Patent 0 3,334,564 APPARATUS FOR CARRYING OUT A DIFFUSION TRANSFER PROCESS Harm Kleinstra, Utrecht, Netherlands, assignor to A. B.

Dick Holland N.V., Utrecht, Netherlands, a limitedliahility company of The Netherlands Filed Nov. 12, 1963, Set. No. 322,939 (llaims priority, application Netherlands, Nov. 23, 1962, 285,862/62; Sept. 30, 1963, 298,581/ 63 7 Claims. (Cl. 9589) ABSTRACT OF THE DISCLOSURE An apparatus for carrying out a diffusion transfer process in which a light-sensitive sheet material and a receiving sheet material are pressed together between a pair of cooperating press rolls arranged above the liquid level of a processing tank, after the sheet materials have been treated with a treating solution contained in the tank. The tank contains a pair of applicator rolls, each one of which cooperates with one of the press rolls in order to apply a treating solution to each of the sheet materials when they are passed between one of the pairs of cooperating press rolls and applicator rolls, and means above the liquid level for guiding the separate sheets from beyond the applicator rolls to the cooperating press rolls.

This invention relates to a process and a device for carrying out a transfer process, and in particular the diffusion contact process, in which light-sensitive sheet material imaged by exposure is pressed against receiving sheet material, after the sheet materials have been wetted with a developing liquid. Such devices are known in many embodiments. In this connection, reference can be made to the US. Patent No 2,762,281.

In carrying out the diffusion contact process in the known devices both the exposed negative sheet material and the positive sheet receiving material are wetted when passed through the liquid in a liquid tank.

It is now found that excellent copies can be obtained by wetting one of the sheet materials only at the contact side with developing liquid with the aid of one or more applicator rolls.

Consequently, according to the invention in a process as defined above at least one of the sheet materials is wetted at the contact side with the developing liquid by means of one or more applicator rolls.

The sheet material may be wetted at the contact side with the developing liquid, while the other side is in contact with a conveying roll. The sheet materials may be pressed against each other by means of rolls, on which at least one of the said materials is wetted at the contact side by means of one or more applicator rolls. In this connection it is remarked that by the contact side of the sheet material the side is meant which is contacted with the other sheet material.

The invention also relates to a device for carrying out the process according to. the invention, comprising a liquid tank, a pair of cooperating press rolls above the liquid level and guiding members for two sheet materials, which is characterized by the fact that the guiding members have been arranged relative to the liquid tank so that the sheet materials are not passed through the liquid in the liquid tank, while one or more applicator rolls are arranged so that at the one side they are in contact with the liquid in the liquid tank and at the other side with at least one of the sheet materials, when these, passing over the guid- 3,334,564 Patented Aug. 8, 1967 ing members, are conducted through the device. The device may be constructed so that the guiding members of each sheet material consist of a conveying roll, which also functions as a press roll, and a curved guiding surface, which conducts the sheet material to the place where the two press rolls are in contact with each other.

In a preferred embodiment of the invention the applicator rolls, which Wet the contact sides of the sheet materials, rotate in a direction opposite to the direction in which the sheet materials are moved. In this embodiment it is possible to have considerably less developing liquid in the liquid tank than when the applicator rolls rotate in the same direction as the direction of movement of the sheet materials. By arching the bottom of the liquid tank inwardly, it is possible to work with very litttle developing liquid in the liquid tank, which is an advantage since it reduces the risk of parts of the device being contaminated by the developing liquid if the device is accidentally displaced during use.

Spraying members may be provided with the aid of which the surface of the applicator rolls are provided with developing liquid.

The surface of the receiving rolls may consist of hard rubber. If desired a roughened surface or a surface provided with grooves can be applied.

In a modification the shafts of the applicator rolls are hollow and provided with openings through which the developing liquid can be supplied via these rolls. In this case these rolls consist of liquid permeable material, e.g. felt, which facilitates arranging the applicator rolls with respect to the conveying rolls or press rolls.

Thus it is an object of this invention to provide a method and means for the development of an image by diffusion transfer wherein only one side of the sheet, including the exposed negative or the receiving copy sheet, is wetted with developing fluid, and it is a related object to provide a means whereby the one side of the sheet is wetted with the developing fluid, as by an applicator roll having one portion submerged in the fluid for transfer of fluid onto the one side of the sheet during passage of the sheet in contact with a portion of the roller extending outside of the fluid, thereby to avoid the necessity for immersion of one or both of the sheets in the fluid.

These and other objects and advantages of this invention will hereinafter appear and, for purposes of illustration, but not of limitation, embodiments of the invention are shown in the accompanying drawings in which FIG. 1 is a schematic sectional elevational view showing one modification of a device for use in the practice of this invention;

FIG. 2 is a schematic sectional view of a modification in the device which may be used in the practice of this invention;

FIG. 3 is a schematic sectional elevational view showing a still further modification in the device which may be employed in the practice of this invention; and

FIG. 4 is a schematic sectional elevational view showing another modification in the device for use in the practice of this invention.

In FIG. 1 the liquid tank 1 is provided with a supply channel 2 for the receiving material 2', upon which the positive must .be printed.

The exposed material 3', upon which consequently the negative is present, is supplied via the guiding surface 3. Above the last part thereof a second guiding surface 4 is present at the upper side.

The receiving material 2' is supplied to the press roll 5, which cooperates with the press rolls 6, to which the 9 material 3', upon which the negative is formed, is sup- 3 plied. While the two sheet materials 2' and 3' are respectively moved around the driven press rolls 5 and 6 they are wetted with the liquid 7 present in the liquid tank 1 by means of the applicator rolls 8 and 9 respectively, which are immersed in the developing liquid and at a level above the liquid are in Contact with the rolls 5 and 6. The guiding surfaces 10 and 11, which may consist of a wire grate, guide the two sheet materials to the place 12, where the two press rolls 5 and 6 are in contact with each other. Above the press rolls 5 and 6 the material 2' upon which the positive has been formed, can, in the usual way, be drawn away from the material 3' upon which the negative was present. Since only the contact sides of the two sheet materials are wetted with liquid, the positive dries very quickly.

In the embodiment shown in FIG. 2 the arrangement of the several parts of the device has been changed somewhat with respect to that of the device according to FIG. 1. As a consequence, the sheet receiving material 2, upon which the positive must be formed, is contacted a shorter time with the developing liquid, which is supplied by means of the applicator roll 8 from the tank 1. In this way also excellent prints can be obtained.

In the embodiment shown in FIG. 3, two applicator rolls 8 and 8" and 9 and 9 respectively are present for both sheet materials. Moreover the material upon which the positive must be formed is not supplied through a channel but via a guiding surface 13, the exposed material upon which the negative is present being supplied between the guiding surfaces 14 and 15.

In the embodiment shown in FIG. 4, the liquid tank 1 is provided with an arched bottom, as a consequence of which very little developing liquid is present in this tank. By means of a supply apparatus (not shown) which operates according to the bird-bath principle, the level of the liquid in this tank can be kept constant.

A sheet 2' upon which the positive is to be printed is supplied via a guiding surface 13, whereas the material 3, upon which by exposure a negative has been applied of an image to be reproduced, is supplied between the guiding surfaces 14 and 15.

Thereupon the conveying roll 18 which cooperates with the press roll 5 and the conveying roll 19, which cooperates with the press roll '6, take over the conveyance of the sheet materials.

The guiding surfaces 10 and 11, which for instance consist of a metal grate, lead both sheet materials to the place 12, where both press rolls 5 and 6 are in contact with each other.

The applicator rolls 18' and 19 are arranged so that they are not in contact with the press rolls 5 and 6, whereas the guiding surfaces 10 and 11 are mounted so that the sheet materials come into contact with the applicator rolls 19' and 18' respectively.

As before, the material upon which the positive has been formed can be drawn from the sheet, upon which the negative was present, above the press rolls'5 and 6. Because only the contact side of both sheet materials is wetted with liquid, the positive dries very quickly.

It will be understood that changes may be made in the details of construction, arrangement and operation, without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. A device for carrying out the diffusion transfer copy process from an exposed negative sheet to a receiving sheet in the production of copy comprising a tank for containing developing liquid, a pair of cooperating press rolls arranged above the level of liquid in the tank in an intermediate portion thereof, a pair of applicator rolls, one of which is arranged with a part of its peripheral surface in contact with the liquid in the tank and with another part of its peripheral surface adjacent the peripheral surface of one of the press rolls of the pair above the liquid level with the other applicator roll having a part of its peripheral surface adjacent the peripheral surface of the other press roll of the pair above the liquid level, means for guiding one of the sheets between the one applicator roll and the one press roll of the pair whereby its outer surface is in contact with the peripheral surface of the applicator roll for wetting the sheet with the developing liquid and means for feeding the other sheet between the other applicator roll and the other press roll of the pair, and means above the liquid level for guiding the separate sheets from beyond the applicator rolls to the cooperating press rolls whereby the wetted surface of the one sheet is pressed into engagement with the outer surface of the other sheet for passage of the sheets through the device without passing below the liquid level.

2. A device as claimed in claim 1 in Which said last mentioned guide means consists of a conveying roll which also functions as a press roll and a curved guiding surface that conducts the sheet material to the area where the press rolls are in contact with each other.

3. A device as claimed in claim 1 in which the one applicator roll portion adjacent the one press roll is in contact with the peripheral surface of the press roll above the liquid level.

-4. A device as claimed in claim 1 in which the other applicator roll has a part of its peripheral surface in contact with the liquid in the tank whereby the outer surface of the other sheet is wet with developing liquid during passage between the other applicator roll and the other press roll of the pair.

5. A device for carrying out the diffusion transfer copy process from an exposed negative sheet to a receiving sheet in the production of copy comprising a tank for containing developing liquid, 'a pair of cooperating press rolls arranged above the level of liquid in the tank in an intermediate portion thereof, a pair of applicator rolls, one of which is arranged with a part of its peripheral surface in contact with the liquid in the tank and with another part of its peripheral surface adjacent the peripheral surface of one of the press rolls of the pair above the liquid level with the other applicator roll having a part of its peripheral surface adjacent the peripheral surface of the other press roll of the pair above the liquid level, means for guiding one of the sheets between the one applicator roll and the one press roll of the pair whereby its outer surface is in contact with the peripheral surface of the applicator roll for wetting the sheet with the developing liquid and means for feeding the other sheet between the other applicator roll and the other press roll of the pair, means above the liquid level for guiding the separate sheets from beyond the applicator rolls to the cooperating press rolls whereby the wetted surface of the one sheet is pressed into engagement with the outer surface of the other sheet for passage of the sheets through the device without passing below the liquid level, said applicator rolls being spaced from the peripheral surfaces of the press rolls and which includes means for rotating the applicator rolls in a direction opposite the direction of movement of the sheet material.

6. A device as claimed in claim 5 which includes con-- veyor rolls separate and apart from the applicator rolls and arranged with their peripheral surfaces in contact with the peripheral surfaces of the press rolls.

7. A device for carying out the diffusion transfer copy process from an exposed negative sheet to a receiving sheet in the production of copy comprising a tank for containing developing liquid, a pair of cooperating press rolls arranged above the level of liquid in the tank in an intermediate portion thereof, a pair of applicator rolls, one of which is arranged with a part of its peripheral surface adjacent the peripheral surface of one of the press rolls of the pair above the liquid level with the other applicator roll having a part of its peripheral surface adjacent the peripheral surface of the other press roll of the pair above the liquid level, means for wetting the peripheral surface of at least the one applicator roll with developing liquid, means for guiding one of the sheets between the one applicator roll and the one press roll of the pair whereby its outer surface is in contact with the peripheral surface of the applicator roll for Wetting the sheet with the developing liquid and means for feeding the other sheet between the other applicator roll and the other press roll of the pair, and means above the liquid level for guiding the separate sheets from beyond the applicator rolls to the cooperating press rolls whereby the wetted surface of the one sheet is pressed into engagement with the outer surface of the other sheet for passage of the sheets through the device without passing below the liquid level.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 12/1960 Germany. 1/1962 Germany.

NORTON ANSHER, Primary Examiner. 15 FRED L. BRAUN, Assistant Examiner. 

1. A DEVICE FOR CARRYING OUT THE DIFFUSION TRANSFER COPY PROCESS FROM AN EXPOSED NEGATIVE SHEET TO A RECEIVING SHEET IN THE PRODUCTION OF COPY COMPRISING A TANK FOR CONTAINING DEVELOPING LIQUID, A PAIR OF COOPERATING PRESS ROLLS ARRANGED ABOVE THE LEVEL OF LIQUID IN THE TANK IN AN INTERMEDIATE PORTION THEREOF, A PAIR OF APPLICATOR ROLLS, ONE OF WHICH IS ARRANGED WITH A PART OF ITS PERIPHERAL SURFACE IN CONTACT WITH A PART OF ITS PERIPHERAL ANOTHER PART OF ITS PERIPHERAL SURFACE ADJACENT THE PERIPHERAL SURFACE OF ONE OF THE PRESS ROLLS OF THE PAIR ABOVE THE LIQUID LEVEL WITH THE OTHER APPLICATOR ROLL HAVING A PART OF ITS PERIPHERAL SURFACE ADJACENT THE PERIPHERAL SURFACE OF THE OTHER PRESS ROLL OF THE PAIR ABOVE THE LIQUID LEVEL, MEANS FOR GUIDING ONE OF THE SHEETS BETWEEN THE ONE APPLICATOR ROLL AND THE ONE PRESS ROLL OF THE PAIR WHEREBY ITS OUTER SURFACE IS IN CONTACT WITH THE PERIPHERAL SURFACE OF THE APPLICATOR ROLL FOR WETTING THE SHEET WITH THE DEVELOPING LIQUID AND MEANS FOR FEEDING THE OTHER SHEET BETWEEN THE OTHER APPLICATOR ROLL AND THE OTHER PRESS ROLL OF THE PAIR, AND MEANS ABOVE THE LIQUID LEVEL FOR GUIDING THE SEPARATE SHEETS FROM BEYOND THE APPLICATOR ROLLS TO THE COOPERATING PRESS ROLLS WHEREBY THE WETTED SURFACE OF THE ONE SHEET IS PRESSED INTO ENGAGEMENT WITH THE OUTER SURFACE OF THE OTHER SHEET FOR PASSAGE OF THE SHEETS THROUGH THE DEVICE WITHOUT PASSING BELOW THE LIQUID LEVEL. 